/*
 * Copyright (c) 2018 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <asm.h>

#define SYSCALL_ENTRY_SIZE 0x04
.global _current_stack

FUNCTION (x86_syscall)
        #copy stack from uthread
        mov $_current_stack,%esp
        mov (%esp),%esp
        sti
        push %ebx /* Ring 3 return address */
        push %ebp /* Ring 3 esp */

        push %ecx
        push %edx
        push %esi
        push %edi

        /* syscall table is long. Multiplocation to find offset */
        mov $SYSCALL_ENTRY_SIZE, %ecx
        mul %ecx  /* Result is stored in eax */
        mov $syscall_table, %edx
        add %edx, %eax
        call (%eax)

        pop %edi
        pop %esi
        pop %edx
        pop %ecx

        pop %ecx  /* pop esp */
        pop %edx  /* pop eip */

        sysexit
